1. SCHOOL OF RENEWABLE ENERGY (SCORE) MAEJO UNIVERSITY CHIANG MAI, THAILAND Methods Objectives Performance Analysis of Mulberry Paper Handmade Dryer by Using Downdraft Gasifier Results มุ่งมั่นพัฒนาบัณฑิตสู่ความเป็นผู้อุดมด้วยปัญญา อดทน สู้งาน เป็นผู้มีคุณธรรม และจริยธรรม เพื่อพัฒนาพลังงานรองรับวิกฤตการณ์พลังงานของประเทศ To analysis of the performance of mulberry paper handmade dryer by using downdraft gasifier. Churat Thararux* Tel.(+66) 081-530-4028 Fax.(+66)5333-3194 Email: Churat_thararux@hotmail.com The performance analysis of a mulberry paper dryer was found that the drying temperature was the principal factor affecting the drying rate and the drying time: as the drying temperature increases, the drying rate is higher and treatment of the drying time is shorter. In contrast, airflow rate and the chain conveyor speed have little effect on the drying rate. The energy consumption is varied with the drying temperature and air mass flow rate. The specific energy consumption (SEC) is increased with the low produce moisture content. The suitable drying condition of the mulberry paper dryer is 80 °C of the drying temperature, 0.04 kg/s of air mass flow rate and 0.29 m/min of the chain conveyor speed. The full capacity of a mulberry paper dryer is about 20 sheets per hour. The fuel (charcoal) consumption rate is 5 kg/h and the electricity is 0.05 kW·h-1. The average specific energy consumption (SEC) of mulberry paper drying is about 741.83-46.86 kJ/g water evaporated. Besides the fact, the simulation results were close to the experimental data. The drying curve of the mulberry paper at 70, 80 and 90 °C drying temperature and at 0.03, 0.04 and 0.06 kg/s air mass flow rate were determined. During initial stage of drying, there was rapid moisture removal from the produce, which later decreased with increase in drying time. The drying process of the mulberry paper is mainly controlled by diffusion mechanism as shown in Fig.2. And the results of the simulation compare with the experiment as shown in Fig. 3. Fig. 1 The schematic concept operation of a mulberry paper continuous dryer and the picture of mulberry paper continuous dryer with a down draft gasifier unit. Feature of mulberry paper continuous dryer: This dryer is a continuous drying system as shown in Fig.1. A papers pulp screen frame is placed on the chain conveyor. Most of moisture is removed at this step, the first step, as it is passing the water sucker. This sucker operated by an air blower which provides vacuum effects on the vacuum nozzles is installed under the chain conveyor rail. When the screen frame is passing these nozzles, the water in the mulberry paper pulp is sucked out about 25% then moves into the tunnel dryer, the second step, where hot air is supplied from a down draft gasifier. When the mulberry paper pulp explores to the hot air, its moisture is then evaporated. At the end of the tunnel dryer, the mulberry paper pulp is dried and mulberry paper is arrived as shown in Fig. 1. Fig.3 Comparison of simulation and experiment moisture content of mulberry paper at drying temperature 80 o C, air mass flow rate 0.04 kg/s, conveyor speed 0.29 m/min Fig.2 Effect of drying temperature on the average moisture content (MC) at air mass flow rate 0.04 kg/s